Telegraph system



Jan. 30, 1934. H. H. HAGLUND TELEGRAPH SYSTEM Filed Jan. 19. 1931 3Sheets-Sheet l oo wwf? Snnentor ff. IY. Hagluu Gttorneg ll .l

TELEGRAPH S YS TEM Filed Jan. 19, 1931 3 Sheets-Sheet 2 M Q 5 N ,BrushCor/'ec for Lttorneg Jan. 30, 1934.A H. H. HAGLUND TELEGRAPH SYSTEM 3Sheets-Sheet 3 Filed Jan. 19, 1931 lhvwentor H ff. 12892287282 47Mmfr-Mw Gttomeg Patented dan., 3@ 1345i TELEGRAPH SYSTEM Applicationl.'Ianuary i9,

9 Claims.

This invention relates to electric signaling sysn tems but moreparticularly to telegraph systems and to arrangements for operatingtelegraph receiving or repeating apparatus direct from the output of anampliner or magnifier.

In my prior applications Ser. Nos. 335,963 and 343,109, l have disclosedsignaling systems wherein the usual electro-mechanical relay devices maybe eliminated by employing thermionic tubes of the so-called thyratrontype which have the characteristic of starting into operation when acer-1 tain positive potential is applied to the grid and continuing tooperate thereafter unaffected by the grid potential.

in tubes of the thyratron type the grid merely surrounds the cathode toform a shield between the anode and the cathode. i'. have discoveredthat if the grid of a mercury vapor or other gaslled valve isconstructed to completely enclose or envelop the cathode and is formedci reticulated material or wire having a very :Eine mesh, the tube willpossess characteristics cuite distinct from the thyratron. The currentwill start bem tween the anode and the cathode the instant predeterminedpositive voltage is applied to the grid and will continue to flow atsubstantially maximum value unal'ected by variations in the gridpotential so long as it remains positive but will stop suddenly theinstant a certain critical negative potential is applied to the grid.

The operation of the tube in this manner is probably as follows-When thegrid is made pos-= itive, there is a flow of electrons from the cathodethrough the small apertures in the grid to the anode. lThese electronscollide with the atoms of the gas, causing ionization and therebystart-1 ing the arc. lf the grid is new made negative by a certaincritical value, positive ions collect and form a sheath about the wiresor structure of the grid in the manner described by Dr. rving Lang-1muir, but since the apertures are very small this sheath is madesufiiciently thick to overlap and eectively block the ionic path throughgrid and as the cathode is completely enclosed or enveloped by the gridstructure, the arc is completely choked oii or extinguished andLie-ionization takes place. 'This tube may therefore be characterized asa gaseous controlled rectier wherein the grid so completely encloses orenvelopes the cathode and has a mesh of such dimensions that the arc canbe started by applying positive potential to the grid and can beextinguished by applying a negative potential thereto.

The object of my invention is to provide an elec-n trical system whereinthermionic tubes control 1931. Serial No. 509,798

(Cl. l'l-Jl) the reception or repeating of recurring mpulses and arethemselves started and stopped by the application ci the correspondingpositive and negative potentials to the grids of the tubes.

For the purpose ci disclosing this invention y and discovery l shallrefer in the following description to the accompanying drawings inwhicln- Figure l is a diagram illustrating an arrangement embodying myinvention for repeating sig`== Mv wire grid having the characteristicswhich l have Zit described.

in Fig. l I have indicated at 6, the output of an ampliier or magnifierot a signal receiving apparatus connected by conductor 'l with the continuous ring of a rotary repeater RR oi the usual e@ well-knownconstruction. The segments a, l), c, etc. are connected alternately tothe grids or two thermionic tubes T1, T2 of the construction de@ scribedin which the cathodes are completely ericlosed or enveloped by the tinemesh grids. The cathodes are connected in parallel to the otherconductor 8 of the ampliner output through a conductor 9 and resistanceR1. The plates or an-1 odes of the tubes are connected respectivelythrough. the actuating coils ci the sendingon re= lays SR1 and SR2,-through the conductor lo and battery BA to the amplier output conductor8. The relay' armatures t1 and t2 are normally biassed to their letthand or negative polarity contacts by the biassing coils bc.

Let us assume that the received signaling im@ pulses have a maximum often volts positive and a minimum of ten volts negative and that theamplifier output is normally biassed to five volts positive so thatthere will be an available positive voltage of fifteen volts and anavailable minimum voltage ef ten volts at the terminals of the ammlpliiier. Also assume that there is a voltage drop or" live volts acrossthe resistance R when current iows through one tube and a drop of tenvolts when current hows through both tubes.

The illustration of the transmitted signal with square topped waves isof course, not attained in actual practice. The diagram of receivedsignals shows that there is a lag between the transtilt recorded. Thediagran cates that the regenerated s the outg dot innnlf in detail.

amplifier. ing through both tubes ther of lil volts across resistancethus leaving t? volts positive to be applied. to 1. tube, therci itstongue or armature is; againf right hand contact. Consequently the tubeil... v/ill continue to operate and the sending brush engages thesegment b', the repeated signal. will continue as a maximum positiveimpulse from the tongue in.

When the brush lli the segment c, the received signal at zero and thevoltage at the amplifier output :is l5 volts po.. .ve Both tubes arestill in operation and hence there is a drop of 1U volts acrossresistance Ri to be subtracted, leaving a resultant oi' 5 volts negativewhich applied to the grid of tube T1. This stops the tube and the tonguet1 of relay SR1 is moved by its biassing coil to the left hand contact.As the sending brush now engages the segment c', the repeated signalimpulse transmitted to the outgoing line changes from maximum positiveto minimum negative, as indicated by the diagram.

When the brush B1 moves onto 4the segment d, the received signal is at aminimum l0 volts negative which is reduced by the 5 volts positive biasto 5 volts negative at the terminals of the amplifier. Since the tube T2is still operating, there is a drop of 5 volts across the resistance R1giving a resultant of 10 volts negative to be applied to the grid oftube T2. This stops tube T2 and causes the tongue t2 of sending-on relaySR2 to move over to its left hand contact under the control of itsbiassing coil. Accordingly as the sendingon brush B2 engages segment dthe negative im pulse being transmitted to line is continued from tonguet2.

When the brush B1 has reached the pickfup segment e, the amplifier'output has dropped to its no signaly value, due to the fact that aseries of single impulses are coming in and the at tenuation of thecable is assumed to be so great that these signals are almost completelylost in transmission. 'Ihe voltage at the amplifier output is 5 voltspositive due to the positive bias. Since neither tube is operating,there is no drop at the resistance R1 and hence the 5 volts positive isapplied to the grid of tube T1 which starts it into operation, therebyenergizing the relay SR1 and moving its tongue t1 over to its right handcontact. As the sendingmn brush B2 engages the contact e', the repeatedsignal impulse shifts from negative to positive as indicated.

This will sufiice to explain the operation. It will be observed that thetubes are started and are also stopped by the received signal impulses,whereas when the thyratron tubes are employed, as in my priorapplications` it is necessary to provide a special rotary transmitter tostop the operation of the tubes. My present invention. therefore.greatly slmplies the apparatus re quired and consequently enhances theefficiency and permits of greater speed.

l. e grid oi tube T2. This and holds ov/n in u. I

ditional or parallel s ci the one or it may be the saine one the cuitbeing paralleled with. the lin this arrangement also cniplc 7 d opacross a resistance the dls-V output tributor is nais, re

s from ne the brush 1 yhe tube iii will operate.

ol such value that the cruieut t1 urn produces a drop across res tant 'l'dll'icient to prevent tub` .trein stall,- even though the amplifieroutput vol "we is u. roar' um when the next .-l segment is lied by thebrusl'i 3. Under these conditions no cor` rection will be l ade, andwhen the amplifier out put .is again ncgat've, the tube 'Ti' will stop,thus restoring the condition necessary to allow a cor-- section when itis needed.

il 'the distributor brushes need a correction when the anipliner changesto posi ivo, the brush will be in Contact with an A. segment. Thiscauses positive potential 'to be applied to the grid of tube T3,starting Vthe tube and thus operat ing the magnet "ll/i of the brushcorrector. The drop in resistance R2 is not sul'licient to prevent thestarting of tube Ti when the brush engages a i3 segment. Both tubes willcontinue to operato and the corrector magnet will remain energized untilthe amplifier output shifts to negative potential thus stopping bothtubes and restoring the condition necessary for another possible coction when the amplifier again becomes pos tive.

Since 'the correction can only 'taire place when the arnplier output ispositive, no corrections can take place when no signal is being receivedand hence the corrector cannot respond to single or dot impulses.

For the purpose of illustrating another appli cation of my invention Ihave shown in Fig. 3. a circuit arrangement for driving a phonic motorunder the control of the gaseous grid controlled tubes described herein.It will be evident that the tubes Ti and T5 will be alternately startedand stopped by the alternating potentials im pressed upon their gridsfrom the oscillator' through the transformer TR. The diametricallyopposite pairs of poles of the phonic motor PM will be energizedalternately from D. C. source through the difierential meter. A circuitarrangement embodying control tubes oi the type dcscribed greatlysimplifies the operation of syn chronous motors of this and similartypes which. require considerable current and hence do not operate Wellunder the control of electromagnetic relays.

It will be obvious to engineers that my invention 'f is equallyapplicable to Wireless systems and that various arrangements of circuitsand apparatus can be made within the scope of my claims, those disclosedin the accompanying drawings being merely illustrative for the purposeof making a connected to said translating devices, said grid l. i i; ii

.l i) il lilo terrasse being of a nne mesh construction and completelyenveloping said cathode whereby the output circuit is substantiallyunaffected by variations or positive grid potential after being startedthereby but is immediately stopped by a critical negative gridpotential.

2. In a signaling system in which periodic signal impulses of shortduration are transmitted, a signal `responsive means comprising athermionic gaseous tube wherein the grid, anode and cathode elements areso constructed and arranged that when started by a critical positivegrid potential the current flows between the anode and the cathodesubstantially unaffected by variations in positive grid potential but isstopped by a critical negative grid potential, a source of currentconnected to the anode and cathode and means for subjecting the grid tosignal impulses in synchronism therewith.

3. In a signaling system as set forth in claim 2, an electromagneticrelay in circuit with said anode and cathode, a source of potentials, atransmission circuit, and means operating in synchronism with the signalimpulses for connecting said transmission circuit to said source ofpotentials under the control of said relay.

4. 1n an electrical system in which periodic currents of short durationare transmitted, apparatus for increasing the effective length of thereceived impulses, comprising a thermionic gaseous tube characterized byanode, cathode and grid elements so constructed and arranged thatcurrent continues to flow in the anode-cathode circuit irrespective ofvariations in the positive grid potential after being started by apredetermined potential applied to the grid but said current beingstopped by a critical negative lgrid potential, a source of current, anelectro-magnetic translating device, said tube having an input circuitincluding the grid element connected to receive said impulses of shortduration and an output circuit including the anode and cathode elementsand said source of current connected to said translating devices.

5. In a communication system wherein single unit impulses are eithermissing or are too Weak to affect receiving instruments, apparatus forrepeating the received intelligence signals and supplying the missingimpulses, comprising a pair of thermionic gaseous tubes characterized byanode, cathode and grid elements so constructed and` arranged thatcurrent continues to flow in the anode-cathode circuit irrespective ofvariations in the positive grid potential after being started by apredetermined potential applied to the grid but said current beingstopped by a critical negative grid potential, means for alternatelyvconnecting the grids to the signal receiving apparatus in synchronismwith the signal impulses, a source: of current connected to theanode-cathode circuits in parallel relation, and electro-magnetic relaysconnected in said respective anode-cathode circuits. v

6. In a communication system, apparatus for repeating and regeneratingthe received intelligence signals, comprising a pair of thermicnicgaseous tubes characterized by anode, cathode and grid elements soconstructed and arranged that current continues tofrlow in the anode'-cathode circuit irrespective oi variations in positive grid potentialafter being started by a predetermined potential applied to the grid butsaid current being stopped by a critical negative grid potential, meansfor impressing the receiving signal impulses upon the grids alternately,a source of current connected to the anodes and cathodes in parallelrelation, transmitting relays in circuit with the anode-cathode circuitsrespectively, a source of current and a distributor operating tocomplete theconnection of said source to a transmitting circuitsynchronously with the received intelligence signals for predeterminedintervals under the control of said relays.

7. In a system of communication in which signal 'impulses aretransmitted and received, apparatus for increasing the effective lengtho the received impulses, comprising a vapor electric arc device incircuit therewith, arc-sustaining electrodes, means for continuouslyionizing gas Within the device, an electrostatic member within thedevice completely enclosing one electrode for timing the startingofs'uccessive arcs therein by said signal impulses, and electricalconnections for charging said member with a critical negative potentialto stop the successive arcs at predetermined intervals, and means iorutilizing the yenergy of the successive arcs.

8. In a system of communication in which signal impulses are received,apparatus for increasing the effective length of the received impulses,comprising a vapor electric are device having arcsustaimng electrodes,means kfor continuously ionizing gas Within the device, and anelectrostatic member completely enclosing one electrode and operating asa timing element to start and to stop the successive arcs thereindetermined by the signal impulses, said arc being started by theapplication of a predetermined positive charge upon said member, the arccontinuing unaiected by variations in positive potential of said impulsebut instantly ceasing upon the application of a critical negativepotenial to said member.

9. In a system of i communication in which signal impulses are received,apparatus for increasing the 'effective lengthof the received impulses,comprising a pair of vapor electric devices, each provided witharc-sustaining electrodes, means for continuously ionizing gas withinthe device andan electrostatic member com-l pletely enclosing oneelectrode and operating as a timing element to'start and stop thesuccessive arcs therein, means for subjecting said members alternatelyto the received signal impulses to thereby start an arc upon theapplicaarc when the impulse is at zero or negative potential.

Y HAKON H. HAGLUND.

